13 )From the tectonic activity map provided, annual amount of seafloor spread is

Question

13 )From the tectonic activity map provided, annual amount of seafloor spread is shown in cm/year. Calculate how far apart the Atlantic Ocean would be at about 20° S latitude for the following times: 10 years, 20 years, and 50 years. The answers are shown in cm.

3.5, 7.0, 17.5

35, 70, 175

70, 140, 350

100, 200, 500

14

At which type of boundary would you expect to find a volcanic island arc?

transform fault boundary

oceanic-oceanic convergent boundary

continental-continental convergent boundary

divergent boundary

15

What other geologic feature would be associated with a volcanic island arc?

a trench

a river

a sea fan

a mountain ridge

QUESTION 16

On the east side of the Philippine Plate, what feature shows evidence of subduction?

Mariana Trench

Java Trench

Ontong-Java Plateau

East Pacific Rise

QUESTION 17

In which ocean can you find the highest rate of seafloor spread?

Antarctic Ocean

Indian Ocean

Atlantic Ocean

Pacific Ocean

QUESTION 18

The South-east Indian Ridge is moving at a rate between 7.2 and 7.5 cm/year. What is happening with the Australian Plate at its northern side along the Java trench?

It is moving away from the Antarctic Plate

It is subducting beneath the Pacific Plate

It is subducting beneath part of the Eurasian Plate

It is moving away from the Eurasian Plate

QUESTION 19

The Nazca plate is moving eastward. What happens to this plate at its eastern edge?

It subducts beneath the Cocos Plate.

It subducts beneath the South American Plate.

It gets farther away from the Pacific Plate.

It does nothing at all.

QUESTION 20

What is meant by a ridge? What sort of boundary exists where there is a ridge?

An oceanic-continental convergent boundary.

A continental-continental convergent boundary.

A divergent boundary.

A transform fault boundary.

QUESTION 21

The northern edge of the Pacific Plate is subducting. Near what land area is this happening?

Bering Sea.

Hawaii.

Alaska.

Arctic Ocean.

QUESTION 22

The plate boundaries shown as a red line on the map consist of primarily which two types of boundaries?

Subduction zones and divergent boundaries.

Convergent and transform fault boundaries.

Divergent and convergent boundaries.

3.5, 7.0, 17.5

35, 70, 175

70, 140, 350

100, 200, 500

Explanation / Answer

14. An arc shape chain of volcanoes formed above subducting plate known as volcanic arc. When these volcanoes form islands they are known as volcanic island arc. They form when one plate subducts beneath another plate. They form parallel to the oceanic trench. It forms at the oceanic oceanic convergent boundary.

15.SInce volcanic island arc forms parallel to the oceanic trench. So they are associated with trench.

16. Phillipine plate is an oceanic tectonic plate. A convergent boundary exists to the eastern side of the Phillippines plate where the Pacific plate subducts at the Izo-Bonin Trench. The east of the plate include Mariana and Izo-Bonin island forming Izo-Bonin Mariana Arc system. So the Mariana trench shows evidence of subduction to the east of the Phillipines

17. The Pacific, Cocos and Nazca plate are among the fastest moving plates and have highest spreading rates of about 15cm/year. So the Pacific oceans have highest rate of seafloor spread

18. Java trench is an extensive subduction zone in the eastern Indian ocean and is associated with subduction of Indo-Australian plate beneath a block of the Eurasian plate. So it is subducting beneath part of Eurasian plate

19. Nazca plate is an oceanic plate in the eastern Pacific ocean and it is subducting beneath the South American plate along the Peru-Chile trench and the collison of these plates i.e. Nazca and South American Plate results in Andean orogeny. Therefore, it subducts beneath the South American Plate

20. A mountain systems under the oceans known as ridge. Along the ridge two tectonic plates diverges away from each other. So a divergent boundary exists where there is a ridge.

21. Pacific plate is an oceanic tectonic plate beneath the Pacific ocean. The northern edge of the Pacific is subducting beneath the North American plate and forming the corresponding Aleutian trench and Aleutein Island. The Aleutein trench extends 2900 through Gulf of Alaska to Kamchatka. So this is happening near Alaska

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.